Polystyrene plastic compositions containing naphthyl ether flame retardants

ABSTRACT

PLASTIC COMPOSITIONS CONTAINING POLYSTYRENES AND BISARYLOXY COMPOUNDS HAVING THE FORMULA   2-(ARYL-O-ALKYLENE-O-),(Z)M,(A)I-NAPHTHALENE   WHEREIN ARYL IS FROM THE GROUP   (A)I,(Z)M-PHENYL AND (Z)M&#39;&#39;,(A)I&#39;&#39;-NAPHTHYL   Z IS BROMINE OR CHLORINE, M AND M&#39;&#39; ARE INTEGERS HAVING A VALUE OF 1-7, Y IS AN INTEGER HAVING A VALUE OF 1-5, I AND I&#39;&#39; ARE INTEGERS HAVING A VALUE OF 0-2, AND A IS CYANO, NITRO, LOWER ALKOXY, LOWER ALKYL, FLUORINE, DIALKYLAMINO, PHENYL, HALO-PHENYL, BENZYL OR HALO-BENZYL AND ALKYLENE IS A STRAIGHT OR BRANCHED CHAIN ALKYLENE GROUP HAVING FROM 1 TO 6 CARBON ATOMS.

United States Patent Oflice 3,830,779 Patented Aug. 20, 1974 US. Cl. 260-4535 G 18 Claims ABSTRACT OF THE DISCLOSURE Plastic compositions containing polystyrenes and hisaryloxy compounds having the formula wherein aryl is from the group Ai m' Z is bromine or chlorine, m and m" are integers having a value of 1-7, y is an integer having a value of 1-5, i and i' are integers having a value of -2, and A is cyano, nitro, lower alkoxy, lower alkyl, fluorine, dialkylamino, phenyl, halo-phenyl, benzyl or halo-benzyl and alkylene is a straight or branched chain alkylene group having from 1 to 6 carbon atoms.

This application is a continuation-in-part of copending application Ser. No. 260,240, filed June 6, 1972, and now abandoned. The entire specification of this case, Ser. No. 260,240, is to be considered as incorporated herein by reference.

The prior art considered in conjunction with the preparation of this application is as follows: US. 2,130,990; US. 2,186,367; U.S. 2,329,033; US. 3,666,692; US. 3,686,320; US. 3,658,634; German Pat. No. 1,139,636; German Pat. No. 2,054,522; Japanese Pat. No. (72) 14,500 as cited in Volume 77, Chemical Abstracts, column 153737k (1972); Chemical Abstracts, Volume 13, column 448 Chemical Abstracts, Volume 31, column 7045 and Journal of the Chemical Society, pages 2972- 2976 (1963). All of these publications are to be considered as incorporated herein by reference.

The present invention relates to plastic compositions containing polystyrenes. More specifically, the present invention covers plastic compositions containing polystyrenes and certain bis-aryloxy compounds (hereinafter defined) as flame retardants for said plastic compositions.

Polystyrenes and utility thereof are known in the art as exemplified by Polystyrene, W. C. Teach and G. C. Kiessling (Reinhold Plastics Applications Series), Reinhold Publishing Corporation, New York, 1960 and Madern Plastics Encyclopedia 1972-1973, Vol. 49: No. 10A, October 1972, pages 97-99, 161 and 271-272 and which publications are in toto incorporated herein by reference.

The need for flame retarding polystyrenes has also been recognized in the art as exemplified by US. 3,347,822 and US. 3,422,048 and Modern Plastics Encyclopedia, ibid, pages 221, 222 and 456-458 and which publications are in toto incorporated herein by reference. 1

The resultant disadvantages in the utilization of various prior art materials as flame retardants for polystyrenes include, without limitation, factors such as thermal migration, heat instability, light instability, non-biodegradable, toxicity, discoloration and the large amounts employed in order to be etfective. Thus, there is always a demand for a material which will function as a flame retardant in polystyrenes and concurrently will not, by incorporation therein, adversely elfect the chemical and/or physical and/or mechanical properties of the resultant polystyrene plastic composition.

The prior art problem of providing a flame retarded polystyrene composition having desired chemical, physical and mechanical properties has now been substantially solved by the present invention and the above-described disadvantages substantially overcome.

Accordingly, one of the main objects of the present invention is to provide polystyrene plastic compositions which are flame retarded.

Another object of the present invention is to provide a materal for polystyrene plastic compositions which will not substantially adversely effect the chemical and/or physical and/or mechanical properties of said compositions.

A further object of the present invention is to provide a flame retardant which is economic and easy to incorporate into polystyrene plastics without being degraded or decomposed as a result of blending or processing operations.

It has been found that the foregoing objects can be obtained by the incorporation of a new class of 'bis-aryloxy compounds in polystyrene to subsequently provide flame retarded compositions which exhibit outstanding chemical, physical and mechanical properties.

The bis-aryloxy compounds used in the present invention compositions have the formula:

O O(alkylene)0(aryl) In 'Formula I above, aryl is from the group Z is bromine or chlorine; m and m' are integers each independently having a value of 1-7; i and i are integers each independently having a value of 0-2; alkylene is a straight or branched chain alkylene group having from 1 to 6 carbon atoms e.g. CH C H C H C H C H C l-I and CH CH(CH )CH A is from the group cyano aryloxy compounds are shown be- O -OT-O(alkylene)-O-(aryl) 2" Alkylene Illustrative (but without limitation) of some of the present invention bislow:

the exemplary definitions of A, Z, alkylene, aryl, m, m compounds. i, i and y are listed in Table I.

TABLE I Where ary1= (-CN), nitro (NO "lower alkoxy (e.g. --OCH OCH ),'10wer'alkyl e.g. CH3, C2H5, C3H7, C4H9, fluorine, dialkylamino e.g. N(CH N(C H phenyl 'CBH5): halo-phenyl,. benzyl (CH C H5), and halo-benzyl; and 5 y is an integer having a value of 1-5.

In Formula I, the sum of i+m or i'+m' is not greater than 7 and i'+y is not greater than 5.

It is to be understood that all of the compounds falling within the above Formula I and as heretofore defined are generically described herein as bis-aryloxy Compound number .i m w H m k. m mm m n k H HH H a 2% mhm mmmmhmmm mm mm% meme 2% h HH mmmcwmmmm mmnmmnmmmmm mmm m wwwwm CC 222I\ 2C22BC21H22B22C21BB22 COG H w HHHfiHH HHH HCHHCHH(HCHHH 99( w HHH wwwHwwwwwwwwwwwwww wwwww HHH wwwnw 4i4444644444uni:ewwfi 40ccoooncccfloooccoomoocoom 644444.24 44in; ammo 000 nmmfimmmmmfimmfimmfififlHMHHHmmmwmmmmmmmmmmm mmmmm mmmfimmfimemmfifimqmmfimmnmmmmm CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC(CCC(CCCCCCCwOCCCCmwCCCCCCCCOCCCCCCCCCCCCCCCCCCCCC 0001111111111111001000211000111111111111100100021100011111111111110010002110001.1-

u m m m m m m M M W m m m m m m m W W m m m m m m m m m m n 2 53 n n n 2 53 3 $3 U H. HH 2 u \U EHH 2 ..8. Hea e 3: we; Fm m m m mm Hmmem :mm was; 2 3 22 A 22 9 2 3 22 2 4 mNoccH wmmnnm "m n n as mmnnm mm 0 mNoocH wmmnnm m mm m m me CNOOC NCCCCC m m0 m m CO m NCCCCC CO UCNOOC NCCOCC "C n CO F F F F "F: :225:25; 5: 3222322322223005733243113332223222222233543324311333222322322223364374431133522 TABLE I-Contlnued Compound number Z m y A t i Alkylene 2 2 -OCH3 1 1 CH2C(CH2C1)H 3 3 -OCH3 1 1 (CH2):C(CH2C1)2 2 2 CHa 1 1 CH2C(CH2C1)H 2 2 F 1 1 CHzC(CHzCl)2 3 3 -N(CH3)2 1 1 CH2C(GHB!2)H 2 2 5H5 1 1 (CH2)ZC(CBI3)H 2 2 -CoH3Blz 1 1 CH2C(CHzCl)H 2 2 CH:CH5 1 1 CHzC CC 2 2 2 CHzCaHaBr 1 1 CHzC(CHzCl)H 3 3 CoHaCl2 1 1 CHzC(CHzC1)H 3 3 F 1 1 CHzC(CC1a)2 5 5 0 0 CH2C(CH2C1)H 4 3 0 0 CH2C(CH2C1)H 3 3 1 1 CH2)2C(CH2C1)2 3 3 O 0 H2C(CH2C1)HCH2 2 2 0 0 CHaC(CCla)H 4 4 0 0 CH2C(CHBr2)H 3 3 2 2 CH2C(CHzOl)H 1 1 1 1 cmcwmonfi 1 1 1 1 (CH2)aC(CHzOl)H In general, the bis-aryloxy compounds are prepared zm A by reacting a halogenated naphthol with a halogenated 0 0N8 alkane or a monohalophenoxy haloalkane (depending upon which bis-aryloxy compound is desired) at elevated O O X(a1kylene) o 0 temperatures in the presence of a basic material such as alkali metal hydroxides, carbonates, bicarbonates, oxides Ar and hydrides. The preferred alkali metals are potassium (IV) (V) andsodium. Where one desires to increase, for example, l ease of handling the reaction mass, solvents such as ke- A tones (e.g. acetone, methyl ethyl ketone, and methyl iso- Zm butyl ketone), alcohols (e.g. methanol, ethanol, iso-propyl alcohol, butyl alcohol and glycols), or aqueous 501- o (alkylenko vents (e.g. water, a mixture of water and alcohol and a mixture of water and ketone) can be employed. The desiredend product, i.e. the bis-aryloxy compound, can Ai be recovered from-the reaction mass via various methods In the above reaction, X is halogen, preferably chlosuch as distillation .or crystallization after cooling the rine, and alkylene is the same as defined herein. reaction mass to about l0-30 C. and adding water The above reactions are conducted at temperatures thereto. Where the end product requires recovery via crysranging from the freezing point of the initial reaction tallization, various aromatic solvents such as benzene, mass to the boiling point thereof. Preferably the tempertoluene, xylene, dichlorobenzene and the like can be used. atures are from about C. to about 200 C. and more Specifically, the bis-naphthoxy compounds are prepared 40 preferably from about C. to about 175 C. It is to according to the following reactions: be understood that the reaction can be conducted under sub-atmospheric (e.g. A atmospheres), atmospheric or super-atmospheric (e.g. 1.5-10 atmospheres) pressure. Zm Preferably, the reaction is carried out at atmospheric 2HX pressure.

OH X(a1.ky1en)X The above-described processes can be carried out with O I (III) conventional, readily available chemical processing equip- W ment. For example, a conventional glass-lined vessel l provided with heat transfer means, a reflux condenser (II) F and a mechanical stirrer can be advantageously utilized Z in practicing any of the preferred embodiments of the invention described in the example set forth herein. O-(alkylene)0 The amount of bis-aryloxy compound employed in the (I) present invention compositions is any quantity which will etfectively render the polystyrene containing composition flame retardant. In general, the amount used is from about 1% to 25% by weight, based on the total weight of the composition. Preferably, the amount employed is from about 5% to about 20% by weight. It is to be In 2 gg z fi gf gg 22 understood that any amount can be used as long as it a e g Pg i does not substantially adversely eifect the chemical and/ 1 1 sfi g i enated or physical and/or mechanical properties of the end poly- 3:? mo f 2 r f disimnar his? mer composition. The amount utilized, however, is such 0 use g eqmva en por 10m 0 amount which achieves the objectives described herein. gersla e i 3 t l r 10X com ounds It is to be understood that the term polystyrene as used pee ca 3" f e unsylilme y g f herein means polymers containing more than 60% styare PE or accor mg to e o owmg rene (phenylethylene, vinyl benzene, styrol, cinnamene) reacnons' C H CH=CH or other unsaturated aromatic monomers comprised of variously substituted styrenederivatives; Zn] 111' This term also includes rubber modified impact-resistant base 0N8 polystyrene and styrene-acrylonitrile copolymers (some- 0 O -s- HOH tlmes referred to in the trade as SA or SAN).

Thus the polystyrenes used in the present invention compositions is any polystyrene herein defined and which one so desires to flame retard. It is to be understood that (11) (IV) 7 the polystyrenes used can be a virgin material, i.e.

substantially free of additives such as stabilizers, plasticizers, dyes, pigments, fillers, and the like, or the polystyrenes can have additives (such as those mentioned and described herein) already contained therein or added concurrently with or after the addition of the bis-aryloxy compounds.

Another facet of the present invention relates to the use of certain metal compounds with the bis-aryloxy compounds to promote a cooperative effect therebetween and thus enhance the flame retardancy of the resultant plastic composition as compared to the flame retardancy of either one component used separately. These enhancing agents are from the group antimony, arsenic, bismuth, tin and zinc-containing compounds. Without limitation, examples of said enhancing agents include Sb O SbCl SbBr SbI SbOCl, AS203, As O ZnBO BaB O -H O, 2-ZnO-3*B O ,-3.5H O and stannous oxide hydrate. The preferred enhancing agent is antimony trioxide.

The amount of enhancing agent employed in the present invention compositions is any amount which when used with said bis-aryloxy compounds will promote a cooperative etfect therebetween. In general, the amount employed is from about 1% to about 15%, preferably from about 2% to about by weight, based on the total weight of plastic composition. Higher amounts can be used as long as the desired end result is achieved.

It is also within the scope of the present invention to employ other materials in the present invention compositions where one so desires to achieve a particular end result. Such materials include, without limitation, adhesion promoters; antioxidants; antistatic agents; antimicrobials; colorants; flame retardants such as those listed on pages 456-458, Modern Plastics Encyclopedia, ibid, (in addition to the new class of flame retardants described herein); heat stabilizers; light stabilizers; pigments; plasticizers; preservatives; ultraviolet stabilizers and fillers.

In this latter category, i.e. fillers, there can be mentioned without limitation, materials such as glass; carbon; cellulos'ic [tillers (wood fluor, cork and shell flour); calcium carbonate (chalk, limestone, and precipitated calcium carbonate); metal flakes; metallic oxides (aluminum, beryllium oxide and magnesia); metallic powders (aluminum, bronze, lead, stainless steel and zinc); polymers (comminuted polymers and elas-tomer plastic blends); silica products (diatomaceous earth, novaculite, quartz, sand, tripoli, fumed colloidal silica, silica aerogel, wet process silica); silicates (asbestos, kaolimite, mica, nepheline syenite, talc, wollastonite, aluminum silicate and calcium silicate); and inorganic compounds such as barium ferrite, barium sulfate, molybdenum disulfide and silicon carbide.

The above mentioned materials, including fillers, are more fully described in Modern Plastics Encyclopedia, ibid, and which publication is incorporated herein (in toto) by reference.

The amount of the above described materials employed in the present invention compositions can be any quantity which will not substantially adversely effect the desired results derived from the present invention compositions. Thus, the amount used can be zero (0) percent, based on the total weight of the composition, up to that percent at which the composition can still be classified as a plastic. In general, such amount will be from about 0% to about 75% and specifically from about 1% to about 50%.

The bis-aryloxy compounds can be incorporated into the polystyrenes at any processing stage in order to prepare the present invention compositions. In general, this is undertaken prior to fabrication either by physical blending or during the process of forming polystyrenes per se. Where one so desires, the bis-aryloxy compounds may be micronized into finely divided particles prior to incorporation into the polystyrenes.

8 EXAMPLE I A polystyrene plastic material, (Union Carbide TMDE 6500, a high impact polystyrene product free of additives) is utilized as the base resin in order to prepare 26 formulations (plastic compositions). With the exception of formulation No. 1, the particular bis-aryloxy compound (and the antimony trioxide enhancing agent where indicated) is incorporated into the plastic by adding both to a Brabender mixer (Plastic-Corder, Torque Rheometer,

Model PLV-lSO, C. W. Brabender Instruments 'Inc., South Hackensack, N.J.). The mixer is equipped with a pair of roller type blades positioned within a head provided with heat transfer means.

The resultant mixture is heated to about 245 C.; at

this temperature, it is in a molten state. The percentages by weight of each component utilized in the respective formulations are listed in'Table II. Each formulation is discharged from the mixer and upon cooling solidifies and is ground into chips. The chips are subjected to compression molding in a Wabash press by placing said chips between two platens, the bottom of which contains four equal size depressions three inches by five inches by /s inch deep. The top platen is then placed over the bottom platen and heat transfer means supplied thereto in order to melt said chips and thus provide solid samples (after cooling) for testing.

Portions of the solid samples of each respective formulation (Nos. 1-26) prepared according to the above described procedure are then subjected to two different standard flammability tests, i.e. UL 94 and ASTM D-2863-70. The UL 94 is, in general, the application of a burner to a test specimen (strip) for a certain period of time and observation of combustion, burning, and extinguishment. This procedure is fully set forth in Underwriters Laboratories bulletin entitled UL 94, Standard for Safety, First Edition, September 1972 and which is incorporated herein by reference. ASTM No. D- 2'8'63-70 is a flammability test which correlates the flammability of a plastic specimen to the available oxygen in its immediate environment; this correlation is stated as an Oxygen Index, 0.1., level predicated upon the percent oxygen in the gaseous medium which is required to just provide a steady state of continuous burning of the plastic specimen. This ASTM method is fully described in 1971 Annual Book of ASTM Standards-Part 27, published by the American Society for Testing and Materials, 1916 -.Race Street, Philadelphia, Pa; this publication is to be considered as incorporated (in toto) herein by reference.

The results of these flammability tests are shown in Table II.

TABLE II.FLAMMAwILITY DATA FOR POLYSTYRENE PLASTIC COMPOSITIONS C COMPOUNDS ONTAINING BIS ARYLOXY Bis-aryloxg i Enhauc- O compoun ng agent, xygen Formulation SbzOa, index,

number Number Percent percent percent UL 94 1 0 0 18.0 Burns 2 20 0 22.5 SB 2 20 10 32.0 SE-O 5 20 0 22.0 SB 5 20 10 30.0 SE-O 15 20 0 21.0 SB 15 20 10 28.5 SE-l 27 20 0 22.5 SB 27 20 10 30.5 SB() 33 20 0 21.5 SB 33 20 10 29.5 810-0 40 20 0 22.0 SB 40 20 10 29.0 SE-l 53 20 0 22.0 SB 53 20 10 30.5 SE-O 58 20 0 21.0 SB 58 20 10 29.0 SE-l 20 0 21.5 SB 65 20 10 28.5 SE-l 73 20 0 23.0 SB 73 20 10 30.0 813-0 77 20 0 22.5 SB 77 20 10 31.0 SE-O 83 20 0 21.5 SB 83 20 10 30.0 SE-O 91 20 10 30.5 SE-O Referring to Table II, the bis-aryloxy number relates to the structural formulae heretofor set forth in Table I; a difference of 2% in the Oxygen Index values is considered significant; and the UL 94 values are on a graduated scale wherein the highest degree to lowest degree of flame retardancy is respectively SE-O, SE-l, SE-2, SB and Burns. I

The results shown in Table H demonstrate the unique effectiveness of these bis-aryloxy compounds as flame retardants for polystyrene. Specifically, formulation No.

1 (the control) had a 0.1. of 18.0 and UL 94 value of Burns. In Nos. 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24, the use of the particular bis-aryloxy compound results in a significant increase (3.0- .0% in fire retardancy as measured by 0.1. (While these formulations had a SB rating, UL 94, the individual UL. rating has a wide range of values and thus the 01. number is, in this case, more indicative of increased flame retardancy.)

The use of an enhancing agent such as Sb O to promote a cooperative effect between such agent and the bis-aryloxy compound is fully demonstrated via the results obtained from testing formulation Nos. 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25 and 26. The highest UL 94 ratings and significantly higher 0.1. values (10.5- 14.0% increase) are obtained.

EXAMPLE II Example I is repeated twice; once using a bisaryloxy compound level and 3% Sb O level and secondly, and 5% levels respectively. At both levels, the 0.1. values and UL 94 datings are slightly lower than the 10% levels of Example I.

EXAMPLE III Portions of the solid samples of Formulation Nos. 1-26 prepared according to the above described procedure of Example I are subjected to the following ASTM tests in order to ascertain other properties of the resultant plastic composition:

(1) Tensile Strength (at break) ASTM Test No. D638-61T; (2) Flexural Strength: ASTM Test No. D790-63; (3) Flexural Modulus: ASTM Test No. D790-63; (4) Notched Izod Impact: ASTM Test No. D 6-5 6 and (5) Heat Distortion Temperature (HDT): ASTM Test No. D648-56.

Each of the aforementioned ASTM Tests are standard tests in the art and are utilized collectively in order to ascertain the efficacy of a polymeric system as an overall flame retarded composition for commercial application. All of these ASTM Tests are to be considered as incorporated herein by reference.

The results of these ASTM tests show that the physical properties of the present invention compositions are basically the same (except Cl. and UL 94 values) as the plastic material without the flame retardant (i.e. formulation No. 1). Thus, there is no substantial adverse-effect on the physical properties of the plastic material when the novel compounds are incorporated therein.

EXAMPLE IV pounds in the above described plastic material as flame retardants therefor is quite unique since it is not possible to predict the effectiveness and functionality of any particular material in any polymer system until it is actively undergone incorporation therein and the resultant plastic composition tested according to various ASTM Standards. Furthermore, it is necessary, in order to have commercial utility, that the resultant flame retarded plastic composition possess characteristics such as being nontoxic. Use of these compounds in the plastic material has accomplished all of these objectives.

The above examples have been described in the foregoing specification for the purpose of illustration and not limitation. Many other modifications and ramifications will naturally suggest themselves to those skilled in the art based on this disclosure. These are intended to be comprehended as within the scope of this invention.

What is claimed is:

1. A plastic composition containing polystyrene having incorporated therein a flame retardant which is a bisaryloxy compound having the formula: 1

n I' l y-o-(au: 1ene)--o- 1 i wherein aryl is from the group A i' Z m' and I8 5) Z is selected from the group consisting of bromine or chlorine; m and m are integers having a value of 1-7; y is an integer having a value of l-5; i and i are integers having a value of 0-2; A is selected from the group consisting of cyano, nitro, lower alkoxy, lower alkyl, fluorine, dialkylamino, phenyl, halophenyl, benzyl or halo-benzyl; and alkylene is a straight or branched chain alkylene group having from 1 to 6 carbon atoms.

2. The composition as set forth in claim 1 wherein alkylone is C H 3. The composition as set forth in claim 1 wherein alkylene is C H 4. The composition as set forth in claim 1 wherein alkylene is C H 5. The composition as set forth in claim 2 wherein Z is bromine.

6. The composition as set forth in claim 2 wherein Z is chlorine. 7. A plastic composition containing polystyrene havmg mcorporated therein a flame retardant which is a bisaryloxy compound having the formula:

Z is selected from the group consisting of bromine or chlorine; m is an integer having a value of 1-7; y is an integer having a value of 1-6; i and i' are integers having a value of 0-2; A is selected from the group consisting of cyano, nitro, lower alkoxy, lower alkyl, fluorine, dialkylammo, phenyl, halo-phenyl, benzyl or halo-benzyl; and alkylene is a straight or branched chain alkylene group having from one to six carbon atoms.

8. The composition as set forth in claim 7 wherein alkylene is 0 H 9. The composition as set forth in claim 7 wherein alkylene is C l-I 10. The composition as set forth in claim 7 wherein alkylene is C H .1 1 11. The composition as set forth in claim 8 wherein Z is bromine.

12. The composition as set forth in claim 8 wherein Z is chlorine.

13. A plastic composition containing polystyrene having incorporated therein a flame retardant which is a bisaryloxy compound having the formula:

14. The composition as set forthin claim .13 wherein alkylene is C H 15. The composition alkylene is C H 16. The composition as set forth in claim 13 wherein alkylene is C H 17. The composition as set forth in claim 14 wherein Z is bromine.

18 The composition as set forth in claim 14 wherein Z is chlorine.

as set forth in claim 13 wherein References Cited UNITED STATES PATENTS 4/1972 Yanagi et al 161-403 2/1973 Kutner 26045.95 G

MAURICE I. WELSH, Primary Examiner 

